EP-4735537-A1 - SEALING COMPOSITION

Abstract

The present invention relates to a composition for sealing different substrates such as paper substrates or cementitious material substrates. It also relates to a sealing coating, in particular for sealing against water, formed from a composition of said type. It further relates to a method for sealing a roof, terrace, balcony, plumbing unit or facade by forming a coating of said type.

Inventors

• TEULERE, CORALIE
• RIEGERT, Maeva
• LEIVA MUÑOZ, Raul

Assignees

• Saint-Gobain Weber France

Dates

Publication Date

20260506

Application Date

20240627

Claims (18)

1. A sealing composition, which is an aqueous dispersion comprising: water, particles of a poly(vinyl acetal)-based resin, particles of a resin other than a poly(vinyl acetal)-based resin, one or more plasticizers, and one or more emulsifiers, wherein the total content of resin particles is 5 to 50% by weight.
2. The composition of claim 1, wherein the poly(vinyl acetal) based resin is poly(vinyl butyral) based.
3. Composition according to claim 2, in which the poly(vinyl butyral) based resin comprises residual alcohol and acetate functions.
4. Composition according to claim 2 or 3, in which the poly(vinyl butyral)-based resin comes from the recycling of laminated glazing.
5. Composition according to any one of claims 1 to 4, further comprising one or more crosslinking agents, preferably chosen from silanes, preferably from alkoxysilanes optionally comprising a functional group reactive with respect to carboxylic acid, carboxylate or hydroxy functions, such as an epoxy or amine group.
6. Composition according to claim 5, in which the weight ratio between the content of crosslinking agent and the content of resin based on poly(vinyl acetal) is between 0.001 and 0.10, in particular between 0.002 and 0.06.
7. Composition according to any one of claims 1 to 6, further comprising one or more fillers, the filler content preferably being between 5 and 80% by weight, relative to the total weight of the composition.
8. Composition according to claim 7, in which the fillers are chosen from calcium carbonate, clays, talc, dolomite, mica, silica sands, ground basalt, barium sulfate, kaolin, and mixtures of two or more of these compounds.
9. A composition according to any one of claims 1 to 8, wherein said resin other than a poly(vinyl acetal) based resin is selected from styrene-acrylic resins, styrene-butadiene resins, acrylic resins, alkyd resins, and a mixture of two or more of these resins, preferably from alkyd resins.
10. Composition according to any one of claims 1 to 9, further comprising from 0.1 to 20% by weight of pigments, relative to the total weight of the composition.
11. Composition according to any one of claims 1 to 10, in which the total weight content of emulsifier(s) is between 0.1% and 10%.
12. Composition according to any one of claims 1 to 11, in which the weight ratio between the plasticizer content and the poly(vinyl acetal)-based resin content is between 0.1 and 1, in particular between 0.2 and 0.5.
13. Composition according to any one of claims 1 to 12, in which the amount of water is between 10 and 70% by weight, in particular between 20 and 60% by weight, relative to the total weight of the composition.
14. Composition according to any one of claims 1 to 13, in which the weight ratio between the content of particles of resin other than a resin based on poly(vinyl acetal) and the content of particles of a resin based on poly(vinyl acetal) is between 0.05 and 20, preferably between 0.1 and 10, or even between 1.0 and 3.0.
15. Waterproofing coating, obtained by applying and drying a composition as defined in any one of claims 1 to 14.
16. Use of a sealing coating as defined in claim 15 as a water-proofing coating.
17. A method of waterproofing a roof, terrace, balcony, damp room or facade comprising applying, to a substrate of said roof, terrace, balcony, damp room or facade, a composition according to any one of claims 1 to 14, to form a coating, then drying said coating to obtain a dry coating preferably having a thickness ranging from 0.1 to 2.0 mm.
18. The method of claim 17, wherein the substrate is made of cementitious material.

Description

Waterproofing composition The present invention relates to a composition for waterproofing various substrates such as paper or cementitious material substrates. It also relates to a waterproof coating, in particular a water-proof coating, formed from such a composition. It further relates to a method for waterproofing a roof, a terrace, a balcony, a damp room or a facade, via the formation of such a coating. Many compositions have been developed to make various substrates waterproof. For example, in the construction sector, to waterproof roofs, terraces, balconies, wet rooms or facades, bituminous or synthetic membranes are used, assembled by welding, hot-poured asphalt coatings, or systems called in the art "liquid waterproofing systems" (SEL). The latter consist of materials based on polymeric resins implemented in one or more layers by projection or by application with a roller, brush or squeegee. Different types of resins are used, in particular polyesters, acrylics, neoprene bitumens, or polyurethane resins. Very durable and easy to apply, these systems generally allow pedestrian traffic directly after drying, eliminating the need for heavy protection. However, the mechanical performance, water resistance and durability of these systems still need to be improved. Another application related to the construction field concerns the sealing of paper bags used for packaging plaster or cement-based powders. Paper bags require protection against the penetration of atmospheric water vapor through the layers of the bag, in order to avoid degradation of the packaged powders. The waterproof bags known for this application are notably made of polyethylene sheets inserted between the two paper plies of the bag, which however make the paper bag non-recyclable. To make paper bags recyclable and waterproof to water vapor, one strategy is to replace the current bags with a recyclable two-ply bag without a plastic-based sheet, in which one of the plies would have a coating based on a very thin polymer, to ensure good water barrier properties. Films based on bio-based polyesters that are more environmentally friendly have been developed. However, these require a heating step at a temperature higher than the melting point of the polymer and generally too high for paper. The invention therefore aims to propose a composition which makes it possible to form a waterproof coating (or membrane): - compatible with different substrates, in particular cementitious materials and paper, - can be dried quickly at room temperature, - offering very good barrier properties to liquid or vapor water, - presenting improved performances, in particular in terms of mechanical properties, water resistance and durability. Another aim of the invention is to provide a waterproofing coating (or membrane) which has a reduced carbon footprint. Thus, the present invention relates to a sealing composition, which is an aqueous dispersion, comprising: water, particles of a poly(vinyl acetal)-based resin, particles of a resin other than a poly(vinyl acetal)-based resin, one or more plasticizers, and one or more emulsifiers, wherein the total content of resin particles is 5 to 50% by weight. In some embodiments, the poly(vinyl acetal)-based resin is poly(vinyl butyral)-based. In some embodiments, the poly(vinyl butyral) based resin includes residual alcohol and acetate functionalities. In some embodiments, the poly(vinyl butyral)-based resin is derived from the recycling of laminated glazing. In certain embodiments, the composition further comprises one or more crosslinking agents, preferably chosen from silanes, preferably from alkoxysilanes optionally comprising a functional group reactive with respect to carboxylic acid, carboxylate or hydroxy functions, such as an epoxy or amine group. In some embodiments, the weight ratio of crosslinking agent content to poly(vinyl acetal) resin content is between 0.001 and 0.10, especially between 0.002 and 0.06. In some embodiments, the composition further comprises one or more fillers, the filler content preferably being between 5 and 80% by weight, relative to the total weight of the composition. The fillers may be selected from calcium carbonate, clays, talc, dolomite, mica, silica sands, ground basalt, barium sulfate, kaolin and mixtures of two or more of these compounds. In some embodiments, said resin other than a poly(vinyl acetal) based resin is selected from styrene-acrylic resins, styrene-butadiene resins, acrylic resins, alkyd resins, and a mixture of two or more of these resins, preferably from alkyd resins. In some embodiments, the composition further comprises from 0.1 to 20% by weight of pigments, relative to the total weight of the composition. In some embodiments, the total weight content of emulsifier(s) is between 0.1% and 10%. In some embodiments, the weight ratio of plasticizer content to poly(vinyl acetal)-based resin content is between 0.1 and 1, especially between 0.2 and 0.5. In certain emb